User Manual
Applications Information
MOTOROLA MC13192 Product Preview 15
7 Applications Information
Figure 7 shows a basic application schematic for interfacing the MC13192 with an MCU. Table 9 lists the
Bill of Materials.
The MC13192 has differential RF inputs and outputs. These are well suited to balanced PCB antenna
structures. Alternatively, chip antennas or other single-ended structures can be used with commercially
available chip baluns or microstrip equivalents. PAO+ and PAO- require connection to VDDA, the analog
regulator output. This is best accomplished with microstrip lines which are decoupled to act as harmonic
traps. The 16 MHz crystal should be mounted close to the MC13192 because the crystal trim default
assumes the listed Toyocom crystal and the 9 pF capacitors shown are used. If a different crystal is used, it
should have a load capacitance of 9 pF or less. Bypassing capacitors are critical and should be placed close
to the device. Unused GPIOs and contacts should be grounded as shown.
The SPI connections to the MCU include IRQ
, CE, MOSI, MISO and SPICLK. The SPI can run at any
frequency of 8 MHz or less. Optionally, CLKO can provide a clock to the MCU. The CLKO frequency is
programmable via the SPI and has a default of 32.786+ kHz. The ATTN
line can be driven by a GPIO
from the MCU or can be negated by a switch or other hardware. The latter approach allows the MCU to be
put in a sleep mode and then awakened by CLKO when the ATTN
line wakes up the MC13192. RXTXEN
can be used to initiate receive or transmit sequences under MCU control. In this case, RXTXEN must be
controlled by an MCU GPIO with the optional connection shown. Otherwise, RXTXEN is held high and
receive or transmit sequences are initiated by an SPI command. Device reset (RST
) can be controlled
through an optional connection to an MCU GPIO or by an external pull-down.
When used in Stream Mode, as with 802.15.4 MAC/PHY software, MC13192 GPIO1 functions as an “Out
of Idle” indicator and GPIO2 functions as a “CRC valid” indicator and are not available for general
purpose use.
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